A noble, chivalrous, and spirited young knight from Thrace, served the Emperor of Constantinople and Greece, who had the bad luck one day near Constantinople to chase his sparrowhawk over a garden wall and find the supposedly dead and buried Empress Fenice sleeping naked with her lover Cligés.
Thus discovered, Cligés sliced one of Bertrand’s legs off below the knee. Bertrand escaped anyway to take his report to Emperor Alis. Thus forcing Cligés and Fenice to flee Greece.
His surname refers to an ancient region in the east Balkan peninsula, now divided between Greece and Turkey.
What happened to Bertrand after that, Chrétien does not say, but his case illustrates the moral ambiguities of this romance: Bertrand, though functioning as betrayer, is far less blameworthy in the matter than the betrayed hero and heroine, and the loss of his leg seems most unjust.
Source
Cligés | Chrétien de Troyes, late 12th century